Carcassonne 3rd edition 7. Siege and Defense

Carcassonne 3rd Edition Expansion 7: Siege and Defense
In this Carcassonne expansion, the city and its surroundings have been attacked by invaders. Make your subjects defenders to strengthen the defense lines and earn points. However, you may lose areas if you invest too little in defense.
This expansion can only be used with the base Carcassonne game.
It can be combined with other expansions.